diff --git a/src/c/num_co.d b/src/c/num_co.d
index a5acae0ae..0d21740f9 100644
--- a/src/c/num_co.d
+++ b/src/c/num_co.d
@@ -780,11 +780,11 @@ round_double(double d)
 	if (d >= 0) {
 		double q = floor(d + 0.5);
 		d -= q;
-		if (d == 0.5) {
+		if (d == -0.5) {
 			double x = q / 10;
 			int i = (int)(10 * (x - floor(x)));
 			if (i & 1) {
-				return q+1;
+				return q-1;
 			}
 		}
 		return q;
@@ -800,11 +800,11 @@ round_long_double(long double d)
 	if (d >= 0) {
 		long double q = floorl(d + 0.5);
 		d -= q;
-		if (d == 0.5) {
+		if (d == -0.5) {
 			long double x = q / 10;
 			int i = (int)(10 * (x - floorl(x)));
 			if (i & 1) {
-				return q+1;
+				return q-1;
 			}
 		}
 		return q;